Modelling is ... easy?

Like the vast majority of software, there's the well travelled superhighway you can drive down rip-roaringly fast (or faster), and there's the jungle you're lucky if you get a machete to hack through the undergrowth with.

UrbanSim's proverbial superhighway is the existing types of models. If you can explain the difference between an Allocation Model and a Location Choice Model, you'll enjoy being able to quickly configure such models in the OPUS GUI (or worst case, modifying the underlying XML file).

If like me, you're still learning that difference, the best places to start seem to be:

1. The OPUS Users Guide and Reference for v4.3, Chapter 14 - Model Types in OPUS. A good amount of detail on the basic theory (though not the implementation) of Simple, Sampling, Allocation, Regression and Choice models.
2. The OPUS walkthrough tutorials on Creating New Models
1. Creating an Allocation Model
2. Creating a Regression Model

Of course if these models are insufficient for your needs, you'll be like me, looking for the machete (or hopefully bulldozer) to get through the jungle. At least for me, I'm coming back to the same core, it's not the syntax, it's the semantics. But the syntax helps in establishing context from which you learn to improve your understanding of semantics.... or something like that. It can be frustrating, which is probably a good thing.

/rant on

It can be an indicator that things like compiling your own code from source are in many cases too complex for even many IT professionals to deal with. And who has the time anyway?

On another note, UI has evolved. When you realise how the vast majority of iOS (which now has been force bundled with XCode for a 3.5GB download just to get XCode 3.2.5), Mac, PC, Android, Windows Phone 7, and web applications expose all text or actions to the user as big shiny buttons. My pet peeve so far is OPUS needs so much right-clicking on models, scenarios, indicators (and probably much more)....that important contextual information is not in the GUI exposed to the user, but hidden in menus the user must explicitly ask for.

Add to that learning a Mac...far harder than I expected, especially with the Python 2.6 + SIP + Qt + PyQt4 dependencies taking ages to compile and running into what I strongly suspect is a 32/64-bit compilation issue (of course code for any individual application must be compiled for one or the other, often explicitly) due to [paraphrased]

PyQt4.QtCore

ImportError: ...no suitable image found, did find ../QtCore.so: mach-o, but wrong architecture

/rant off

As one of my professors once said it's:

"where the rubber hits the road".

I suspect the best thing for me to do is probably try finding ways to be more participatory in the OPUS community, i.e. forums and whatever else is on www.urbansim.org

For now, back to coding/testing/debugging fun =)